How your diet can improve your fertility

Paula Goodyer

Leafy green salads, stir fried broccoli, and even Vegemite on wholegrain toast are all good foods for getting your daily folate, a B vitamin that matters if you're pregnant or trying to be. Besides helping prevent birth defects like spina bifida, folate is also important for the quality of eggs and sperm – and too little may reduce the chances of conceiving, says fertility specialist Dr Anne Clark.

Yet Dr Clark sees couples trying to get pregnant who swear they're eating their greens, but who are still showing signs of deficiency. The culprit often turns out to be a maverick enzyme called MTHFR that makes it hard to absorb folate from food. It's not rare either, says Dr Clark, medical director of Fertility First in Sydney's Hurstville. One in eight of us have MTHFR, but the problem is easily fixed by a supplement of folate, and vitamins B6 and B12.

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Dr Clark believes the contribution of lifestyle, including diet, is underrated when it comes to successful conception – that's why Fertility First is one of only a few fertility clinics in Australia that routinely checks to see if nutrition and lifestyle habits might be undermining a couple's chances of pregnancy. As well as screening for nutritional deficiencies, there's a test to check the levels of oxidative stress in sperm – a problem sometimes caused by lifestyle habits like smoking, alcohol, diets low in antioxidants, and pollutants.

"If a man's levels of oxidative stress are high, we get him to quit smoking, reduce alcohol, improve his diet and take dietary supplements and wait for two to three months before trying to conceive again," says Dr Clark, adding that diets with plenty of vegetables fruit and wholegrains provide antioxidants to help prevent damage to sperm's DNA.

"We find that when couples correct nutritional deficiencies and make lifestyle changes, 25 to 30 per cent conceive spontaneously and have a healthy pregnancy without needing IVF or other fertility treatments," she says.

The contribution of lifestyle, including diet, is underrated when it comes to successful conception

One third of men and women tested by Fertility First are also deficient in vitamin D, found in some foods, but made mostly by sunlight. Some research – although not conclusive - suggests this might affect fertility in both sexes. Either way, sufficient vitamin D is critical for the baby's normal development, adds Dr Clark.

What about the impact of too much saturated fat in the diet, recently linked to lower sperm concentration by researchers at Harvard University?

It's too early to say for sure that dietary fat is to blame, and more research is needed, says Professor Rob McLachlan, Director of Andrology Australia, the Australia Centre of Excellence in Male Reproductive Health. Too much body fat, however, may affect fertility in both sexes, especially women where extra weight can disrupt fertility.

In men it may cause subtle hormonal changes, as well as potentially overheating the sperm factory – the testicles.

"The scrotum is an air conditioning unit that keeps testicles two degrees cooler than the rest of the body but for anyone who's sitting all day at a desk or in a truck and is mildly obese testicles can get hot under the fat," he explains.

But although there's much more to learn about the impact of lifestyle on making babies, there's one thing no one can argue with, he adds.

"If you want optimal longevity and to be around for your family then a healthy lifestyle is important."